Curves

Curves are the most precise tonal and color tool in RapidRAW. They come right after Basic in the Adjustments panel.

Channels and modes

The round buttons on the right choose the channel:

L (Luma) changes brightness. It is applied to red, green and blue equally, so a strong curve also changes saturation a little.
R, G, B change one color channel only.

The two buttons on the left choose the mode:

Point Curve: place and drag points.
Parametric Curve: shape the curve with sliders.

The graph shows the histogram of the current channel in the background. Curves you edited on other channels are drawn faintly, so you can see everything at once.

Curves work on the image after the tone mapper and Brightness, so they shape the final look you see.

Point Curve

Horizontal axis: input, from black (left) to white (right).
Vertical axis: output.
A straight diagonal line means no change.

Action	How
Add a point	Click anywhere in the graph. The point appears where you click and can be dragged straight away.
Move a point	Drag it. Hold `Shift` or `Alt` for fine control. Points snap to the left and right edges unless you hold one of these keys.
Delete a point	Right-click it. The two end points cannot be deleted.
Reset the channel	Double-click the graph.
More options	Right-click the graph: Copy this curve, Paste Point Curve, Paste from Parametric Curve, Reset this channel, Reset All Point Curves.

The copied curve stays available while RapidRAW is open, so you can paste it onto another channel or onto another photo.

Between points the curve is smooth and never overshoots, so you won't get sudden bumps. Use up to 16 points per curve; more points are not rendered.

Common curve shapes

S-curve (more contrast): add a point at about a quarter of the way and pull it down a little, and one at three quarters and push it up a little. Highlights get brighter and shadows darker.

Matte / faded look: drag the bottom-left end point straight up to about 20 to 30. Blacks turn into dark grey.

Soft highlights: drag the top-right end point down to about 235. Pure white becomes a soft light grey, good for a film look.

Cool shadows, warm highlights: on the B curve, push the lower part up slightly (bluer shadows) and the upper part down slightly (yellower highlights).

More contrast without touching shadows: add a point in the shadows and leave it on the line to lock them, then add an S-shape only in the upper half.

New to this? Why use curves instead of Contrast, Highlights and Shadows?

The Basic sliders are quick, but each one has a fixed shape. A curve lets you decide exactly which tones get brighter and which get darker. For example, you can add contrast to the midtones while leaving the shadows exactly as they are, which a Contrast slider cannot do.

The R, G and B curves are also a classic way to color-grade: they shift the color of shadows, midtones and highlights separately.

Parametric Curve

Shape the curve with sliders instead of points. This is a fast way to make broad changes that always look smooth.

Below the graph is a strip with three handles (at 25, 50 and 75 by default). They split the tonal range into four zones. Drag a handle to move a border, double-click it to reset it.

Slider	Range	Affects
White Level	−100 to 0	Lowers the brightest output, like pulling the top end point down.
Highlights	−100 to +100	From the right handle to white.
Lights	−100 to +100	Between the middle and right handles.
Darks	−100 to +100	Between the left and middle handles.
Shadows	−100 to +100	From black to the left handle.
Black Level	0 to +100	Raises the darkest output, like a matte look.

Click a number to type a value, double-click it to reset. Right-click the graph to copy, paste or reset parametric curves.

Example for a soft, bright portrait: Lights +15, Darks +10, Shadows −5, Black Level +8.

When you switch between Point and Parametric mode, each keeps its own settings.

In masks